Without limiting the scope of the invention, its background is described in connection with coating of an adhesive, applied and pressure sealed, to form an airtight seal to maintain sterility. Various medical instruments, medical devices, tools, and supplies are subjected to sterilization treatments and packaged sterilely. In the context of packaging, it is particularly important that sterile technique be practiced during sealing and during opening of a package. One important feature of the packaging material is to have good drapeability such that it will readily fall away from a sterilized item as the sterilized package is opened. Another important feature is the sealing of the package to maintain sterility. Often a single coating of adhesive is applied and pressure sealed, in theory, to form an airtight seal in order to maintain sterility; however, in actuality the single coating is susceptible to non-uniform coating and leakage.
For example, U.S. Patent Application Publication No. 2008/0102232, entitled, “Synthetic Based Self Seal Adhesive System for Packaging,” includes a water based self seal adhesive system utilizing a self seal adhesive containing no natural rubber. The self seal adhesive system is a transfer adhesive disposed on a transfer web and an anchor adhesive disposed on an anchor web with the two adhesives forming the seal for the package. The self seal adhesives bond to themselves when pressure is applied to close or seal the packaging material. When peeled apart, the adhesive splits, adhesive fails from either or both the front web and the back web, or destroys one or both of the substrates of the package. Primer coatings may also be used to enhance performance of the self seal adhesive.
For example, U.S. Pat. No. 5,653,090, entitled, “Sterilizable Flexible Pouch Package,” includes a high temperature steam-sterilizable flexible pouch package includes a non-woven barrier web, a perforated plastic intermediate web, and an imperforate plastic upper web. Line heat seals bonding the webs form a cavity into which high temperature sterilizing steam may enter after passing through the barrier and intermediate webs. The line heat seal bonding the upper and intermediate webs is of the delamination failure type. An access opening is provided for insertion of an object to be sterilized into the cavity after which the access opening is sealed, enclosing the object in the cavity. After high temperature steam sterilizing, the package is opened by peeling apart the upper web from the intermediate web which causes a delamination failure of the line heat seal.
For example, U.S. Pat. No. 7,718,433, entitled, “Packaging System for a Sterilized Article,” includes a sterilization pouch. The pouch includes a posterior portion attached to an anterior portion along three edges. The two portions define the pouch. The top part of the pouch is inverted so that the inside part of the pouch is facing outward and forms a cuff around the pouch. An integral internal sterilization indicator is further provided. The integral indicator comprises a sterilizing agent sensitive substance. The sterilizing agent sensitive substance can be an indicator ink printed as an ink line on the interior of the sterilization pouch below the cuff.
For example, U.S. Pat. No. 6,059,112, entitled, “Peel Package,” includes a sterilizable package for medical objects or the like, comprising, a first layer of material, a second layer of film on said first layer, a third layer having a preformed blister formed from film on said second layer, the layers being sealed together in a peripheral seal to form a space between the second and third layers for an object, the seal between the first layer and the second and third layers being releasable by tensile separation of the first layer from the second and third layers, and the second layer having a breakable perforation line at the space whereby the second layer can be broken at the perforation line to expose a portion of the object for direct presentation of the object from one person to another person.
For example, U.S. Pat. No. 6,383,586, entitled, “Formulation,” includes an adhesive composition that is specifically formulated for use in packaging medical products such as catheters between a spun-bonded polyolefin non-woven fabric and an ethylene vinyl acetate copolymer film includes from about 5 to about 65 percent by weight of a low density polyethylene; from about 35 to about 90 percent by weight of an ethylene vinyl acetate copolymers; and from about 5 to about 65 percent by weight of a linear block copolymer having at least one vinyl substituted aromatic hydrocarbon polymer block and at least one polyolefin polymer block made from an aliphatic conjugated diene.
For example, U.S. Pat. No. 6,063,838, entitled, “Blended Pressure-Sensitive Adhesives,” includes a pressure-sensitive adhesive comprising a blend of at least two components, wherein the first component is at least one pressure-sensitive adhesive and the second component is at least one thermoplastic material, wherein the components form a blended composition having more than one domain and, wherein one domain is substantially continuous (generally, the pressure-sensitive adhesive) and the other domain is substantially fibrillous to schistose (generally, the thermoplastic material). The second component can be (a) at least one thermoplastic elastomer, (b) at least one elastomer with a tackifying resin or (c) at least one elastomer. The entire contents of each which are incorporated herein by reference.